<script type="text/javascript">
$(document).ready(function(){
var bro=$.browser;
if(bro.msie) {binfo="Microsoft Internet Explorer "+bro.version;}

if(bro.mozilla) {binfo="Mozilla Firefox "+bro.version;}

if(bro.safari) {binfo="Apple Safari "+bro.version;}

if(bro.opera) {binfo="Opera "+bro.version;}

alert(binfo);

$("#zhankai").click(function(){

$("#tr1").slideToggle();


if($(this).parent().attr("rowspan")!=null&&$(this).parent().attr("rowspan")!="1")
{
//收起
$(this).parent().removeAttr("rowspan");
}
else
{
//展开
$(this).parent().attr("Rowspan","2");
}

});

});
</script>

<table width="100%" border=1>
<tr>
<td><a id="zhankai" href="#">点我展开</a></td>
<td>1</td>
<td>2</td>
<td>3</td>
</tr>
<tr style="display:none" id="tr1">

<td>4</td>
<td>5</td>
<td>6</td>
</tr>
</table>